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Herramientas Destacadas en este Teardown


The FitBit One is part of the family of fitness devices from FitBit Inc, designed to track your movement throughout the day and display the data via a website dashboard.

FitBit One is a wearable device that keeps track of the number and rate of steps you take and stairs you climb, and it uses this information to calculate various metrics like distance covered and calories burned. The device periodically sends the data it gathers to FitBit's servers via wireless communication with internet connected smartphones, iPads, or a PC with dongle.

There are a number of interesting features that warrant the teardown. It has a rechargeable battery that should power the device for about two weeks. It has a haptic alarm for time of day reminders. It has a bright LED display that shows the current statistics, and it is claimed to be sweat proof and rain proof, but not water proof. it also claims to remember minute-by-minute movement stats for up to seven days, and a summary of movement data for much longer.

Time to open it up and see what's inside this mighty machine.

Este desmontaje no es una guía de reparación. Para reparar tu Fitbit One, utiliza nuestros manuales de servicio .

  1. Fitbit One Teardown, Fitbit One Teardown: paso 1, imagen 1 de 2 Fitbit One Teardown, Fitbit One Teardown: paso 1, imagen 2 de 2
    • Removing the metal backplate is simple. This is just stuck on with some flexible glue. So prise something under and off it pops.

    • Inside you can see a number of large cut outs in the rear of the plastic casing.

    • Note the small pinhole in the metal backplate that aligns with the rubber sealed hole in the plastic casing - more on that later.

    • There is also a very small ground out area inside the metal backplate that appears to align with the rotating mass of the vibrator.

  2. Fitbit One Teardown: paso 2, imagen 1 de 2 Fitbit One Teardown: paso 2, imagen 2 de 2
    • The plastic casing is made up of two parts stuck together. Using a precision utility knife, carefully cut along the seam.

    • There are plastic clips at each end that are easy to cut through inadvertently if you go too deep.

    • The front now lifts away cleanly.

  3. Fitbit One Teardown: paso 3, imagen 1 de 2 Fitbit One Teardown: paso 3, imagen 2 de 2
    • Inside the front cover you see the LCD display, attached by ribbon cable and stuck firmly onto the PCB.

    • Above the display, running down the right hand side of the device front, is the BLE antenna.

    • Lifting the LCD glass just results in destroying it, and there is nothing interesting underneath anyway.

  4. Fitbit One Teardown: paso 4, imagen 1 de 2 Fitbit One Teardown: paso 4, imagen 2 de 2
    • The PCB lifts out from the back of the plastic housing easily.

    • Notice how the battery is supported on stand-offs from the rear of the PCB.

    • The battery is held in place with a small foam block adhering to the battery and PCB. Cut that away and the battery lifts off.

  5. Fitbit One Teardown: paso 5, imagen 1 de 2 Fitbit One Teardown: paso 5, imagen 2 de 2
    • Now we get to see some more interesting parts.

    • The SoC has a QR code sticker, likely for inventory control, so take that off to see what we have underneath.

    • You can also see the spring-loaded paddles at the bottom of the PCB that connect to the device charging pins.

    • The power control module for the battery is wrapped up near the battery terminals.

  6. Fitbit One Teardown: paso 6, imagen 1 de 2 Fitbit One Teardown: paso 6, imagen 2 de 2
  7. Fitbit One Teardown: paso 7, imagen 1 de 2 Fitbit One Teardown: paso 7, imagen 2 de 2
    • The air pressure hole, required for the altimeter, is protected by a piece of paper held in place by a foam collar.

    • In turn, the inside of the plastic cover presses onto a foam collar around the altimeter on the PCB.

    • This makes the device sweat proof, but not water tight.

  8. Fitbit One Teardown: paso 8, imagen 1 de 1
    • Too bad the display was damaged during teardown.

    • Looks like a tidy, well-designed bit of tech!

    • Conclusion is that the FitBit One is not an easily repairable device.

    • The device is not designed to be opened, so you will do some damage by cutting it open

    • Taking things apart will compromise the water resistance of the device, and the LCD display is easily broken by any flexing or attempts to modify.

    Awesome! I've always wanted to see inside one of those.

    Kyle Wiens - Contestar

    i don't this particularly interesting because there is nothing that I can apply to fix or modify. So, I'm glad to just see it and move on. It's more interesting to tear down a LED TV to see the modular components and try to diagnose the problem.

    oakland1000 - Contestar

    Took mine apart when it wouldn't come on at all, went for a dip in the beach with it clipped to my pants so I thought that was why. Surprised I was when the inside was immaculate! (I also washed it in the machine twice and dropped it in the sink with running water once) Anyway, did some prodding and poking under my phone camera magnifier app, plugged it into the charger and it came on! The battery won't last through a day again though. Anyone know where I can get a battery to fit?

    [deleted] - Contestar

    Amazon sells the batteries. I purchased a replacement battery for my One a few weeks ago. I am trying to figure out how to open the case without damaging it.

    What tools did you use to take it apart? Any tips or suggestions? Did you glue it back together or will it stay firmly in place after you put it back together? Any help would be appreciated. Thank you in advance!

    Vonda K Robb -

Tim Ellison

Miembro Desde 28/11/13

231 Reputación

1 Guía escrita

27 comentarios

Are there any markings indicating the controller interface for the LED display? Its a nice display, and I'd be curious if the module in my broken Fitbit could be repurposed.

Andrew Villeneuve - Contestar

My Fitbit went through the clothes washer attached to my jeans. When it came out I was amazed it was still working, but after 2 days the display went blank, and it was dead to the world. I tried unsuccesfully to dry it out in rice for a week, but that didn't help at all. I then took the decision to carefully open it as in this guide. I found quite a lot of sulphate corrosion at various places on the board, plus some water droplets inside the case. I cleaned the board with an ear bud dipped in methylated spirits to remove the corrosion, and I dried the water drops carefully with hair dryer. After gluing it together, and charging, it is working perfectly again - I guess not as water tight as before, but I can live with that - so long as it doesn't go through the washer again :P

wayne - Contestar

What type of glue did you use?

Vonda K Robb -

Could anyone tell me what kind of tools I should use to remove the metal back? I spent some time but did not work it out. Thanks.

Elias - Contestar

My Fitbit One fell face down during a wintry mix and drizzle and when I found it, it wasn't working. I put it in a bag of rice for a few hours but it didn't work. I opened it up and everything was remarkably clean and dry, but so far no success in resuscitation!

Chris - Contestar

@Elias, I used a heavy duty razor blade utility knife slipped under the end by the switch, and twisted gently to not damage the finish along the edge. Patience to wait while the glue stretches and releases is key. The same knife along one side of the case was enough to open that as well.

Unfortunately in my washing machine induced case, the corrosion in the battery charging circuit appears to be fatal.

jadeters - Contestar

Others have cleaned up corrosion using a Qtip and solution (alcohol was listed by someone and something by another). You can resolder the battery or order a new one from Amazon. Battery information is: Cameron Sino (that's the company), Model #CS-FTN100SL and Part #LSSP281324AB. The battery has a one year warranty. I will use your tips for opening my One to install the new battery I purchased the first week of July 2021. Good luck!

Vonda K Robb -

Mine recently stopped worked.. opened it and found one of the standoffs for the battery loose and intermittently touching the circuit board causing it to short out.. after removing it and glueing it back together, all seems to be like it was..

kerwinlewis - Contestar

I followed these instructions and the metal back plate took a lot of effort and time to get off. Once that was off the rest came apart easily. I put my Fitbit through the wash and it would work. I found corrosion and cleaned it up with some rubbing alcohol and put the Fitbit back together and it works again! Thanks for the instructions!

Dennis Bird - Contestar

Just fixed mine after a washing in the machine, the black wire on the battery had corroded through, bared back and resoldered, now working fine.

The symptoms were, no life until connected to usb charger then battery level shown as full, and fitbit 6.06 displayed for a few seconds.

John Caldicott - Contestar

My Polymer Li-Ion Battery has swollen to the point that the back pop off. Looks like gas in the battery like it is going to pop. . Can I use a pin to let the gas escape, if it is gas? The case will not close with the battery swollen the way it is.

Mike Comrie - Contestar

Mike, I would recommend replacing it so it doesn't rupture and ruin your One. Order a replacement battery from Amazon. They are between $12 to $15 as of July 2021.

Vonda K Robb -

why would you not start with the conclusions so ppl know what they are getting themselves into?

Kevin G - Contestar

Which one of connector is positive? or does not matter!

Is it possible to charge 5V USB cable... I Lost Charging Unit ;-((

Thanks in Advance...


ademaydin - Contestar

When looking at the back of the FitBit One from outside the case, the left hand side is negative and the right hand side is positive.

roughana - Contestar

Now, can we get a replacement battery? Or hack some other tiny lithium battery in?

As above mine has no life until connected to usb charger then battery level is shown as full, and fitbit 6.06 is displayed for a few seconds.

Bryce Nesbitt - Contestar

Bryce, yes you can order replacement battery. I ordered mine from Amazon July 2021. The company the battery is produced by is Cameron Sino; their Model #CS-FTN100SL and Part # LSSP281324AB. Their batteries have a one year warranty from date of purchase. Good luck!

Vonda K Robb -

What voltage is that battery? What size? Small coin cells in that range are available at DigiKey....

Bryce Nesbitt - Contestar

I purchased one on Amazon July 2021. The company the battery is produced by is Cameron Sino; their Model #CS-FTN100SL and Part #LSSP281324AB. Their batteries have a one year warranty from date of purchase.

Vonda K Robb -

The battery appears to be labeled as “LSSP 281324”, which as far as I can tell is simply a Lithium Polymer battery that is 2.8mm thick x 13mm x 24mm. Does *anyone* know where we could get such a battery, or a similarly sized battery that would fit within the Fitbit One case? I think batteries of this size are nominally 3.7V.

Paul DeFilippo - Contestar

Correct number with AB at the end. I purchased one on Amazon July 2021. The company the battery is produced by is Cameron Sino; their Model #CS-FTN100SL. Their batteries have a one year warranty from date of purchase. Good luck!

Vonda K Robb -

Hi my fitbits just stopped working, won't take a charge nothing got two of them same issue. I miss my fit bit! Any ideas on what might be the problem. Never washed them or dropped them. SMOKIE8196@YAHOO.COM

Kathleen Trapiss - Contestar

You probably need a new battery as the batteries are only designed to last a few years. I have only charged mine when necessary so as not to overcharge it nor decrease the life of the battery. My battery is over 7 years old but will only hold a charge for 1 to 1 1/2 days at most. I ordered a new battery from Amazon; as of July 2021 the price ranges are $12 to $15.

Vonda K Robb -

Where can I buy a new battery for my One?

Martin Abella - Contestar

Amazon sells them and some of the sellers include prying tools and installation instructions. Some sellers have a one year battery warranty but others do not. You will need a soldering gun to remove and install the battery without damaging it. You may be able to find someone to install if you're not comfortable doing so.

Vonda K Robb -

So my new beagle decided to chow down on my One the other day. Fortunately, he only swallowed the silicone of the holder an that came back up later. But he put a dent in the back of the case and the display has gotten progressively lighter, until now I can barely see it. Fortunately, I can still use it for sleep tracking as the haptics are working fine. Any idea what might have been damaged and if it can be saved with a new display perhaps?

Paul Ring - Contestar

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